1. Field of the Invention
The present invention relates to a manufacturing apparatus for a semiconductor device and a manufacturing method for a semiconductor device, which are used for a film formation on a semiconductor wafer by supplying process gas while heating the wafer.
2. Description of the Related Art
In recent years, with demands of further price reduction and high performance of a semiconductor device, there has been required high productivity in a film formation process as well as high quality of the semiconductor device such as improvement in uniformity of a film thickness.
To satisfy such requirements, there has been used an approach to heating a wafer while rotating the wafer at high-speed such as 900 rpm and more, using an Single-wafer-processing type epitaxial film formation apparatus, as disclosed in Japanese Patent Application Laid-Open No. 11-67675. Further, it has been expected that high productivity and improvement in uniformity of a film thickness can be achieved by using inexpensive Cl based source gas such as trichlorosilane (hereinafter referred to as “TCS”) and dichlorosilane in addition to using a wafer having a large diameter, for example, φ300 mm.
However, there is a problem that high productivity is difficult to achieve, when an epitaxial film having a large thickness, for example, more than 150 μm used for IGBT (insulated gate bipolar transistor) is formed.
Furthermore, by supplying the source gas described above onto a wafer, an epitaxial film is formed, and a gas flow to an outer periphery is generated. Such a gas flow reaches a member, for example, a wall surface of a reaction chamber so that a deposited material which is a cause for particles tends to be generated, and upward and downward gas flows are generated.
The upward gas flow stays on the way to an upper wall of the reaction chamber and has an influence upon the film formation capability of a wafer peripheral portion. In addition, the downward gas flow stays before gas exhaust so that the gas flow intrudes into a heater unit and a rotation drive unit for rotating the heater unit and causes clogging due to the resulting deposited material, thus degrading productivity.
Accordingly, a diameter of the reaction chamber may be increased, however, a large apparatus will be required. In addition, purge gas may be introduced into the heater unit or the rotation drive unit, however, a large amount of purge gas will be required, thus causing a problem of high running cost.